Rotary pump



p 1933- J. H. ROWLANDS ETAL 1,927,418

ROTARY PUMP Filed Dec. 1931 2 Sheets-Sheet l P 1933 J. H. ROWLANDS Er AJ. 18

ROTARY PUMP Filed Dec. 1,1951 2 Shets-Sheet 2 Patented Sept. '19, 1933 UNITED STATES ROTARY PUMP John Henry Rowlands, Saundersfoot, and Griffith Thomas, Begelly, Wales Application December 1, 1931, Serial .No; 578,238, and in Great Britain December 31,1930

3 Claims.

This invention relates to rotary pumps of the kind wherein two rotors in rolling contact and provided with intermeshing projections and recesses, are enclosed in two intersecting cylinders furnished with inlet and outlet ports adjacent to their lines of intersection, and has for its object to provide an improved construction whereby increased efliciency and convenience in operation may be attained According to the present invention the intermeshing projections and recesses are arranged helically upon the rotor, the leading part of each projection being furnished on its trailing side with a straight portion extending longitudinally 1 of the rotor. Preferably the inlet port is reduced in width at that side adjacent to the trailing. ends of theproje'ctions. Preferably also, the helical projections 'are of progressingly decreasing thickness from their leading to their trailing ends.

20, The outlet port may be provided with a nonreturn flap -valve constituted by a plurality of valve flaps formed, with the exception of the outer one, with apertures of progressively decreasing areas and being hinged each to the preceding fiap excepting the inner one which is hinged to the pumpframework. The stufiing box glands for the rotor shafts may be formed with teeth at their peripheries so as ,to engage with a pinion mounted upon a shaft carrying a handwheel or the like, so as to be adapted to be rotated simultaneously for tightening the glands.

The invention will be described by way of example with reference to the accompanying drawings of which Figure 1 is an end elevation of a pump with the end plate of the casing removed, Figure 2 isa sectional elevation taken on the line 2-2 of Figure 1, Figure 3 is an elevation of a rotor showing a modification and'Figure 4 is a perspective view of a rotor as illustrated in Figures l and 2 showing the position of the inlet port relatively to the rotor.

As shown in Figures 1 and 2, a rotary pump consists of a casing 11 divided into two similar compartments by means of a plate 12 and closed being furnished with holding-down bolts such as 11a. In each of said compartments is disposed a pair of coacting rotors 15, 16 and 17, 18

of which the rotors l5, l7 and 16,18 are mounted with an inlet 21 and an outlet 22, together with by means of end plates 13 and 14, the casing 11 1 corresponding inlet and outlet ports 23 and 24 respectively, the latter being provided with a non-return flap valve constituted by a plurality of valve flaps 25, 26, 27, 28 and 29 of which-the flaps 25, 26, 27 and 28 are formed with apertures such as 30 of progressively decreasing areas, and

of which the flaps 26, 27, 28 and 29 are hinged each to the preceding flap, the flap 25 being hinged as at 31 to the casing 11.

Each rotor of a pair of coacting rotors such as 15, 16 is formed with two projections such as 32 which are of helical formation for the major part of their lengths and straight for the remainder as at33, the straight portion 33 being at the leading end 33a of the helix, and in particular, on the trailing side 32a of the projection 32. Recesses such as 34 are formed adjacent to the projections on the one rotor for the accommodation of the corresponding projections on the other rotor of the pair.

The inlet port 23 is formed with lips 35 adjacent to the trailing ends of the projections 32 so as to reduce its width at that point, whilst if desired similar lips (not shown) may be provided in the 7 outlet port 24. It will. be appreciated that the 30 lips 35 (dotted lines on Figure 4) cause the inlet port to .close earlier than would otherwise be'the case, and-thus enable the helical projections 32 to be made of smaller pitch without risk of direct communication between the inlet and outlet 35 ports.

The shafts 19 and 20 are geared together at one end by means of pinions 36 and 37 so as to be constrained to rotate at equal speeds, whilst stufiing box glands 38 and 39 serving to make the bearings of the shafts l9 and 20 watertight, are formed at their peripheries with teeth 40 so as to engage with a pinion 41 mountedon a shaft 42 carrying a handwheel 43 for the purpose of tightening said glands equally. The shaft 42 is mounted at one end on the end plate 13 and extends through the wall of a cover 44 which serves to protect the gearing and is furnished with an inspection cover 44a and a drain plug 44b. The shafts 19 and 20 extend through the end plate14 in bearings furnished with-packing glands 38c and 39a similar to the glands 38 and 39.

Adjacent to the outlet port 24 is mounted a pair of rotary brushes or scrapers 45, 45 connected by gearing (not shown) with the rotor shafts 19, 20 so as to be adapted to rotate in contact with the surfaces of the adjacent rotors. Eachscraper 47 is furnished with a sharp edged projection 48, and with bent wire teeth 4'7 similar to those eniployed on card clothing, the arrangement being such thatany foreign matter adhering to the rotors will be removed by the scrapers and carried to the outlet.

Figure 3 shows a modified rotor 48, having a pair of helical projections 49, united by a straight portion 51 at their leading ends, two of such pairs 49, 50 being provided on each rotor.

By means of this invention a rotary pump may be so constructed that greater volumetric efficiency and a more uniform flow of fluid may be attained than heretofore whilst a relatively small pitch helix may be adopted for the helical projections, thus increasing the speed at which the machine may be operated emciently.

We claim:

1. A rotary pump comprising two intersecting cylinders, two power driven rotors in said cylinders, the entire cylindrical surfaces of which rotors are in rolling contact except for two diametrically opposite helical projections and two cooperating recesses adjacent said projections, the

faces of said projections and the adjacent recesses being continuous, the arrangement being such that the projections of one rotor intermesh with the recesses of the other rotor, straight portions extending from the trailing sides of the leading ends of the respective projections and recesses parallel with the axes of the rotors, and inlet and Ill III 

